Note: Descriptions are shown in the official language in which they were submitted.
CA 02343190 2005-09-23
1
THROUGH-TUBING RETRIEVABLE WHIPSTOCK SYSTEM
The present invention is related to: whipstocks and associated apparatus for
use in
wellbores; whipstocks insertable through one tubular into another, e.g., but
not limited to,
through a smaller diameter tubing into a larger diameter casing; whipstock
retrieval;
anchoring apparatus for use in tubulars; and methods of use of such tools and
apparatuses.
A variety of whipstocks and related milling systems are available in the prior
art; e.g., but
not limited to, the devices disclosed in U.S. Patents 5,595,247; 5,452,759;
5,222,554;
io 5,2i 1,715; 5,195,591; 5,109,924; 4,491,178; and 4,266,621.
Whipstocks and whipstock systems are tools inserted in a wellbore for
deflecting a drill bit,
mill, mill-drill, or other tool in a direction that is angularly offset with
respect to the
orientation wellbore. The deflected tool establishes a new or additional
drilling path. in
many instances, a whipstock set in a casing string on an anchor provides an
angled
whipstock surface or whipstock face at a desired depth in a wellbore to
conduct side track
or lateral directional drilling operations through a casing string. The face
of the whipstock
is oriented to position a casing window at a desired radial azimuth relative
to the a3cis of the
casing to provide a new drilling course.
Often a window is formed in a casing string that includes a smaller diameter
tubing string
that terminates at a position above a desired position of the casing window.
Since the
removal of the tubing string requires considerable rig time and expense,
"through tubing"
whipstock systems have been developed for first passing through the tubing
string then
2 5 setting in a casing string at the desired depth for milling or cutting the
window in the casing
string. Once the window has been properly cut in the casing string, a side
track or lateral
drilling operation proceeds in a desired azimuthal direction relative to the
casing string.
Often a drill motor, and a bit rotatable by the drill motor, are suspended
from a coiled
tubing workstring for engaging a set whipstock in a casing string. Fluid is
pumped through
3 o the coiled tubing workstring to drive the drill motor, so that the
rotating bit engages the
whipstock face and begins cutting a window in the casing string with an
operation
involving a single run-in trip of coiled tubing workstring.
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There is a need for an effective whipstock and associated apparatus which is
insertable
through a smaller diameter tubular, such as tubing, and then disposable in a
larger diameter
tubular, such as casing, below the smaller diameter tubular. There is a need
for such
devices which effectively anchor and correctly orient themselves in the larger
diameter
tubular, and which are, in certain aspects, easily retrieved.
What follows are some oi; but not all, the objects of this invention. In
addition to the
specific objects stated below for at least certain preferred embodiments of
the invention,
other objects and proposes will be readily apparent to one of skill in this
art who has the
benefit of this invention's teachings and disclosures. It is, therefore, an
object of at least
certain preferred embodiments of the present invention to provide:
New, useful, unique, e~cient, non-obvious whipstocks, methods for installing
them
through and in wellbore tubulars, and methods of their use;
Such deviocs for insertion through a smaller diameter tubular into a largez
diameter
tubular; in one aspect, for insertion through tubing into casing extending
below the tubing;
Such devices which are settable at any desired location in a wellbore or
tubular;
Such devices which are retrievable;
New parts for such devices;
Such devices for effective anchoring of a whipstock in a tubular, and
Methods of the use of such devices.
According to a first aspect of the present invention there is provided a
whipstock system
for insertion into an earth wellbore through a first tubular into a second
tubular and for
selxtively setting within the second tubular, the first tubular having a
smaller internal
diameter than the second tubular and the first tubular disposed above the
second tubular,
the second tubular has an interior surface, the whipstock system having a
concave, anchor
apparatus connected to and below the concave, grip apparatus movably disposed
within the
anchor apparatus, pushing apparatus below the grip apparatus for pushing the
grip
3 0 apparatus upwardly and outwardly from the anchor apparatus for contacting
the interior
surface of the second tubular to set the whipstock system therein, and fluid
flow apparatus
for conducting fluid under pressure through the concave and through the anchor
apparatus
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to push up on the pushing apparatus.
The grip apparatus may have a grip mating apparatus and the anchor apparatus
including
an anchor body above the grip apparatus, and anchor body mating apparatus for
acting with
the grip mating apparatus to guide movement of the grip apparatus with respect
to the
anchor apparatus; the anchor apparatus including an anchor housing within
which the grip
apparatus is initially located, and grip releasable apparatus reIeasably
holding the grip
apparatus to the anchor housing, wherein the grip apparatus is movable out
from the anchor
apparatus to set the whipstock system and is then movable back into the anchor
apparatus
1 o to facilitate retrieval of the whipstock system from the earth wellbore;
the anchor apparatus
including an anchor body above the grip apparatus, the anchor body having a
fluid flow
channel therethrough, the anchor body below and spaced apart from a lower end
of the
concave, the concave having a fluid flow channel therethrough, and flexible
fluid flow
member interconnecting and in fluid communication with the fluid flow channel
of the
concave and the fluid flow channel of the anchor body; wherein the grip
apparatus is
movable out from the anchor apparatus to push the anchor appa~tatus against a
first part of
the interior surface of the second tubular causing the concave to move against
a socond part
of the interior surface of the second tubular spaced apart from the first
part; holding
apparatus for holding the pushing apparatus up against the grip apparatus to
maintain
2 0 setting of the whipstock system; wherein the holding apparatus is
releasably secured to the
pushing apparatus for selective release thereby allowing the pushing apparatus
to move
down and away from the grip apparatus so that the grip apparatus is movable
back into the
anchor apparatus to un-set the whipstock system; wherein the holding apparatus
includes
a cxntral mandrel connected to the anchor apparatus and running through a
ce~al channel
2 5 through the pushing apparatus, the central mandrel having a portion with
mandrel ratchet
teeth, and the pushing apparatus having a portion with pushing apparatus
ratchet teeth for
ratchetingly acting with the mandrel ratchet teeth to prevent downward
movement of the
pushing ap~rat~c~vhile allowing upward movement thereof to push the grip
apparatus out
from the anchor apparatus; wherein the portion of the pushing apparatus having
the pushing
3 o apparatus ratchet teeth is a separate part releasably secured to the
pushing apparatus for
selective disengagement therefrom to free the pushing apparatus from the
central mandrel
permitting downward movement of the pushing apparatus and un-setting of the
grip
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apparatus; a central mandrel connected to the anchor apparatus and having a
top end and
a bottom end, the anchor apparatus including an anchor housing within which is
disposod
an anchor body positioned above the grip apparatus, the slip apparatus
initially disposed
within the anchor housing above the pushing apparatus, the anchor housing
having a
sealed-off lower end, the pushing apparatus including a pusher sleeve below
the grip
apparatus and a piston below the pusher sleeve, the central mandrel extending
down from
the anchor body, through the grip apparatus, through the pushing apparatus,
and through
the piston, a fluid flow channel through the whipstock system including
channels through
concave, through a member interconnecting the concave and the anchor body, and
through
1 o the central mandrel, and fluid flowable under pressure from earth surface
to the whipstock
system, through the fluid flow channel, and out through at least one lower
exit port at the
bottom end of the central mandrel beneath the piston to force the piston and
thereby the
pusher sleeve upwardly to move the grip apparatus from the anchor housing to
set the
whipstock system within the second tubular, wherein the first tubular
comprises a string
of tubing and the second tubular comprises a string of casing, both strings
disposed in an
earth wellbore and extending down into the wellbore from an earth surface; at
least one
au~ciliary grip member on the anchor apparatus spaced radially apart from the
slip
apparatus; wherein the systan is tubular string is coiled tubing; wherein the
grip apparatus
is from the group consisting of slip apparatus and non marking gripping
apparatus; a
2 0 retrieval tool releasably connected to the whipstock system for removing
the whipstock
system from the earth wellbore; wherein the concave has a top lip slot and a
concave
surface and wherein the retrieval tool has a body, a hollow sleeve connected
to and with a
portion extending down beyond the body, the sleeve having an inns lip for
receipt within
the top lip slot of the concave, a movable manber selectively releasably held
within a body
2 5 channel in the body, a spring in the body channel urging the movable
member outwardly
therefrom, holding apparatus releasably holding the movable member within the
body
charnel, and the movable member movable out from the body channel upon release
of the
holding ap~aratu~to contact the concave surface to stabilize the retrieval
tool on the
concave; whexein the holding apparatus comprises a piston movably disposed
with a piston
3 o channel of the body, the piston releasably connected to the movable member
and positioned
for contact by a top of the concave so that force on the piston releases the
piston from the
movable member thereby freeing the movable member for movement by the spring;
and/or
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wherein the piston has a reduced diameter portion and a dog initially has part
thereof
disposed in a slot in the movable member and part thereof disposed in a
corresponding slot
of the piston to releasably hold the movable member, movement of the piston by
contact
with the top of the concave moving the reduced diameter portion of the piston
adjacent the
dog permitting the dog to move away from the movable member thereby freeing
the
movable member for downward movement with respect to the concave.
According to a second aspect of the present invention there is provided a
method for setting
a whipstock system in a second tubular in an earth wellbore, the whipstoclc
system
comprising a concave, anchor apparatus connected to and below the concave,
grip
apparatus movably disposed within the anchor apparatus, pushing apparatus
below the grip
apparatus for pushing the grip apparatus upwardly a~ outwardly from the a~;hor
apparatus
for contacting the interior surface of the second tubular to set the whipstock
system theran,
and fluid flow apparatus for conducting fluid under pressure through the
concave and
thmugh the anchor apparatus to push up on the pushing apparatus, the method
including
introducing fluid under pmssure through the fluid flow apparatus to move the
pushing
apparatus, and setting the grip apparatus by moving the pushing apparatus
upwardly.
The method may include one, some or all of the following - moving the grip
apparatus
back into the anchor apparatus; and retrieving the whipstock system from the
earth
wellbore; selectively and releasably holding the pushing apparatus up against
the grip
apparatus; moving the grip apparatus out from the anchor apparatus to push the
anchor
apparatus against a first part of the interior surface of the second tubular
and thereby
moving the concave against a second part of the interior surface of the second
tubular
2 5 spaced apart from the first part.
According to a third aspect of the present invention there is provided an
anchor apparatus
for ancho~tg a~i~.ellbore item in a tubular member or in a wellbore, the
anchor apparatus
having a concave, anchor apparatus connected to and below the concave, grip
apparatus
3 o movably disposed within the anchor apparatus, pushing apparatus below the
grip apparatus
for pushing the grip apparatus upwardly and outwardly from the anchor
apparatus for
contacting the interior surface of the second tubular to set the whipstock
system therein, and
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fluid flow apparatus for conducting fluid under pressure through the concave
and through
the anchor apparatus to push up on the pushing apparatus.
The anchor apparatus may comprise one, some or all of the following - an
anchor housing
within which the grip apparatus is initially located; grip releasable
apparatus releasably
holding the grip apparatus to the anchor housing; the grip apparatus movable
out from the
anchor apparatus to set the whipstock system and is then movable back into the
anchor
apparatus to facilitate retrieval of the whipstock system from the earth
wellbore; the grip
apparatus movable out from the anchor apparatus to push the anchor apparatus
against a
first part of the interior surface of the second tubular causing the concave
to move against
a second part of the interior surface of the second tubular spaced apart from
the first part;
holding apparatus for holding the pushing apparatus up against the grip
apparatus to
maintain setting of the whipstock system; and/or the grip apparatus having
slip apparatus.
According to a fourth aspect of the present invention there is provided a
retrieval tool for
retrieving an item from a wellbore, the item having an item lip slot, the
retrieval tool having
a body, a hollow sleeve connected to and with a portion extending down beyond
the body,
the sleeve having an inner lip for receipt within the item lip slot of the
item, a movable
member selectively releasably held within a body channel in the body, a spring
in the body
2 o channel urging the movable member outwardly therefrom, holding apparatus
releasably
holding the movable member within the body channel, and the movable member
movable
out from the body channel upon release of the holding apparatus to contact the
item to
stabilize the retrieval tool on the item.
The retrieval tool may comprise one, some, or ail of the following; such a
tool wherein the
holding apparatus has a piston movably disposed with a piston channel of the
body, the
piston releasably cormected to the movable member and positioned for contact
by a top of
the item so_that_force on the piston releases the piston from the movable
member thereby
freeing the movable member for movement b the
y spring, and the piston has a reduced
3 o diameter portion and a dog initially has part thereof disposed in a slot
in the movable
member and part thereof disposed in a corresponding slot of the piston to
releasably hold
the movable member, movement of the piston by contact with the top of the item
moving
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the reduced diameter portion of the piston adjacent the dog permitting the dog
to wove
away from the movable member thereby freeing the movable member for downward
movement with respect to the item.
According to a fifth aspect of the present invention there is provided a slip
with at lest two
toothed surfaces, including at least a first toothed surface for resisting a
force applied to the
slip in a first direction and a sa;ond toothed surface for resisting a force
applied to the slip
in a second direction different from the first direction; and, in one aspect,
such a slip that
has teeth to resist torsion force and teeth to resist up and down force.
The present invention, in certain embodiments, discloses a through-tubing
whipstock
systan which, in one aspect, is retrievable and which is insertable in a
wellbore through a
smaller diameter tubular (e.g. casing or tubing) into a tubular of larger
diameter (e.g. casing
or tubing). In one aspect, such a system includes a concave to a lower end of
which is
secured an anchor housing that is in fluid communication, via a flexible hose,
with as
anchor body therein. A fluid channel runs through the concave. An upper end of
a mandrel
is housed in a recess in the anchor body. The mandrel's lower end, in one
aspect, extends
out from the anchor housing. A setting slip is disposed below the anchor body
within an
opening in the anchor housing. A pusher sleeve below the slip is selectively
displaced
2 o upwardly by a piston below the pusher sleeve to push the sup out from the
opening in the
anchor housing to set against an interior of a tubular or of a wellbore. Fluid
under pressure
flows from the surface, through the work string, through the concave, through
the anchor
body, to and through the mandrel, exiting the mandrel beneath the piston to
move the piston
upwardly. Initially, a shearable member, e.g. but not limited to a shear pin
or pins, holds
2 5 the slip in place. One or more slips or grip members may be used on the
housing opposite
the movable slip.
The present~nve~on discloses a retrieval tool for retrieving the whipstock
system from
a wellbore. The retrieval tool, in one aspect, has a member that is inserted
into and held
3 0 within a con~esponding recess in the top of a concave while an opposed
portion of the tool
abuts a side of the concave opposite the recess to securely grip the concave
(and thus the
apparatus suspended from the whipstock) for retrieval.
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For a better understanding of the present invention and in order to show how
the same may
be carried irno effect reference will now be made, by way of example, to the
accompanying
drawings, in which:
Fig. 1 is a side cross-sectional view of a whipstock system according to the
present
invention.
Figs. 2A - 2I are enlarged views of parts of the system of Fig. 1.
Figs. 3A - 3G are side cross-sectional views showing steps in the operation of
the
system of Fig. 1.
3 0 Fig. 4A is an enlarged side cross-sectional view of a mandrel of the
system of Fig.
1. Figs. 4B - 4E are enlarged views of part of the m~drel of Fig. 4A.
Fig. SA is an enlarged top view and Fig SB is an enlarged cross-sectional side
view
of an anchor housing of the system of Fig. 1. Fig. SC is a view along line SC-
SC of Fig.
SB. Fig. SD is a view along line SD-SD of Fig. 5B.
Fig. 6A is an enlarged bottom view of a slip of the system of Fig. 1. Fig. 6B
is an
enlarged side cross-sectional view of the slip of Fig. 6A along line 6B-6B of
Fig. 6C. Fig.
6C is a top view of the slip of Fig. 6A. Fig. 6D is a view along line 6D-6D of
Fig. 6B.
Fig. 7A is an enlarged top view of an anchor body of the system of Fig. 1.
Fig. 7B
is an enlarged side cross-sectional view of the anchor body of Fig. 7A. Fig 7C
is a view
2 0 along line 7C-7C of Fig. 7A. Fig. 7D is an enlargement of part of the
system as shown in
Fig. 7B. Fig. 7E is a view along line 7E-7E of Fig. 7B. Fig. 7F is a view
along line 7F-7F
of Fig. 7B.
Fig. 8 is a side view of a prior art flexible hose used with the system of
Fig. 1.
Fig. 9 is a side cross-sectional view of a hose adapter used with the hose of
fig. 8.
2 5 Fig. l0A is a side view of a slip of the system of Fig. 1. .Fig. l OB is
top view of the
slip of Fig. 10A. Fig. l OC is view along_linc l OC-l OC of Fig. 10A.
Figs. 11A is a side cross-sectional view of an anchor bolt of the system of
Fig. 1.
Fig. 11 H is a bottom view along of the bolt of Fig. 1 lA.
Fig. 12A is a side cross-sectional view of a whipstock and whipstock retrieval
tool
3 D according to the present invention. Figs. 12B - 12E are cross-sectional
views at the level
of the apparatus of Fig. 12A at which they are disposed in the drawing. Figs.
12G-12H
show steps in the operation of the apparatus of Fig. 12A.
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Referring now to Figs. 1- 2F, a system 10 according to the present invention
has a concave
14 with an upper end 11 having a hole 12 therethrough for receiving a shear
stud,
connector, or shear pin for releasably connecting a starter mill, milling
assembly, or milling
system to the concave 14. A fluid flow channel 13 through the concave 14
provides a flow
path for fluid under pressure used to activate anchoring apparatus described
below.
The concave 14 is secured e.g. by bolts to an anchor body 20 that has an upper
space 21
through which extends bendable tubular or, in one aspect, a flexible hose 22
that provides
fluid communication between the concave's fluid flow chamiel 13 and a fluid
flow chamiel
23 of the anchor body 20. A slanted surface 24 of the anchor body 20 provides
a surface
against which a slip 30 (described below) is movable to anchor the whipstock
system 10
in a casing 15 in a casing string placed below a tubing string T. A lower
enlarged portion
25 of the fluid flow channel 23 receives an upper end of a mandrel 40
(described below).
The slip 30 is movably disposed in an opening 51 of an anchor housing 50. The
anchor
housing 50 has a bore 53 therethrough. The anchor body 20 is disposed within
the top of
the anchor housing SO and they are welded together. A space 21 is a space in
the anchor
body 20. The slip 30 may have any known and suitable outer gripping member or
surface
2 0 31, marking or non-marking and/or toothed, for engaging an interior
surface of the casing
15. In one aspect the surface 31 has toothed surfaces 35 (which resist axial
displacement)
and 36 (which resist torsion). A lower end 32 of the slip 30 provides a
surface for contact
by an upper end 61 of a pusher sleeve 60 (described below). The mandrel 40
extends
through a slot 34 in the slip 30, down through a channel 63 of the pusher
sleeve 60, and
through a channel 73 of a piston 70. The mandrel's lower end is blocked off
e.g. with a
blocking member 40a thr~eadedly engaged in a lower threaded bore 40b, or with
a plug.
The pushe~,,~lee~60 has screw holes 62 for receiving screws 64 whose inner
ends project
into screw recesses 82 of a ratchet body 80 to secure the ratchet body 80 to
the lower end
3 0 . of the pusher sleeve 60. A channel 83 extends through the ratchet body
80 and the mandrel
40 passes through the channel 83. A latch 84 is held within the ratchet body
80 (e.g. with
a snap retaining ring in a groove 83a that is disposed below and abutting a
lower end of the
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to
latch 84). Pins 89 in pin recesses 82 releasably hold the ratchet body 80 and
the latch 84
to the pusher sleeve 60. A channel 87 extends through the latch 84. Ratchet
teeth 88 are
provided on an inner surface of the channel 87 which are sized and disposed to
ratchetingIy
engage corresponding teeth on the part of the mandrel 40 (described below). In
one aspect
the latch 84 includes a plurality of partial circular segments 84a held
together by garter
springs 86a or other suitable connectors residing in recesses 86. The segments
84a can be
senucircular, a quarter of a circle or any desired segment size.
The piston 70 has a lower body 71 with an O-ring seal recess 72 for an O-ring
seal 74 that
1 o seals the interface between an interior surface of the anchor housing 50
and an exterior
surface of the piston 70. A top end 75 of the piston 70 is disposed to
selectively contact a
bottom end 64 of the pusher sleeve 60.
An end cap 90 is removably positioned in a lower end 51 of the anchor housing
50 and
seals off the lower end of the anchor housing 50. A lower end 41 of the
mandrel 40 passes
through a channel 93 through the end cap 90. An O-ring 94 in an O~ing recess
92 seals the
anchor housing/end cap interface.
Figs. 3A - 3G show steps in an operation ofthe whipstoek system 10. Fig. 3A
shows the
2 0 whipstock system 10 in a "running stage" as in Fig. 1 in which the system
10 is run into a
wellbore W. In one operation the whipstock system 10 is run through a tubing
strings e.g.
with an internal diameter of 3.68"~on coiled tubing with a running tool, or on
a properly
sized drill pipe string with a running tool. A high pressure fluid pumping
system at the
surface provides fluid, e.g. hydraulic fluid, at desired pressure levels to
the system 10 which
flows (see Figs. 3H, 3G'to and through the concave 14, through the flexible
hose 22 and
down through a central fluid flow channel 43 of the mandrel 40 to exit ports
44. Fluid
pressure builds up beneath the piston 70 and urges it and the ratchet body 80
upwardly
against the~ush~sleeve 60, which in turn pushes the slip 30 up, eventually
with su~cient
force to shear a shear pin 33 that releasably secures the slip 30 to the
mandrel 40 and then
3 o outwardly from opening S 1 of the anchor housing 50. The surface 31 of the
slip 30 engages
the inner wall of the casing 15 to anchor the system 10 within the casing 15.
Fig. 3B shows
the slip apparatus 30 moved out from the anchor housing 50 and abutting and
set against
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the interior surface of the casing 15. A slight taper 14a on the lower end of
the concave 14
has facilitated movement of the concave 14 against an opposite side of the
casing 15 and
the flexible hose 22 has flexed or bent to accommodate this movement of the
concave 14.
As the ratchet body 80 is pushed up by the piston 70 and moves up around the
mandrel 40,
the ratchet teeth 88 ratcheringly engage corresponding teeth 48 (see Figs. 4C,
4E) of the
mandrel 40. This prevents the pusher sleeve 60 and the slip 30 from returning
to a position
in which the slip 30 does not engage the inner wall of the casing 15. In cases
in which a
string with a running tool is used to introduce the system t0 into a tubular
string in a
1 o wellbore and move the system 10 through the tubular string, upon release
of the running
tool fluid pressure ceases through the system, the piston 70 no longer urges
the pusher
sleeve 60, and the latch 84 holds the pusher sleeve and thus the slip 30 in an
engaged
position.
As the piston 70 moves up, it compressor a spring 75 disposed about the gel
40, biased
at a lower end against an internal shoulder 76 of the piston 70 and at an
upper end against
the latch 84. In one aspect the spring is sized and configured so that
sufficient spring force
is available when the spring is compressed between about _ to 1 inch, and, in
one aspect,
about %s inch.
In a milling stage shown in Figs. 3D and 3E, the spring 75 has pushed the
piston 70 down
(to the position of Fig. 1 ). In certain aspects, in a second trip, a mill or
mill system uses the
whipstock as a mill diverter and nulls an opening or window through the casing
1 S at a
desired location. When fluid pressure is released (e.g. surface pump system is
turned off)
2 5 the piston 70 moves down.
Figs. 3F and 3G show a releasing stage of the operation in which a retrieval
tool or overshot
engages the~ap the concave to remove the system 10 from the casing 15 and fiom
the
wellbore W (shown in Fig. 3A). A retrieval tool according to the present
invention, e.g. as
3 0 shown in Fig. 16A, may also be used. An upward pull on the system 10
and/or one or more
"jarring" steps applied thereto, e.g. with any well-known jar device, breaks
the pins 89 that
releasably hold the latch 84 and the ratchet body 80, freeing the pusher
sleeve 60 for
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12
downward movement with respect to the anchor housing 50 and the anchor housing
50 for
upward movement with respect to the pusher sleeve 60. This in turn permits the
slip 30 to
re-enter the opening 51 and disengage from contact with the interior of the
casing 15.
As shown in Figs. 3F and 3G, the latch 84 remains i~ place on the mandrel 40
and the
pusher sleeve 60 and piston 70 are again in contact with the slip 30 within
the anchor
housing SO the system 10 assumes the original smaller overall outer diameter
along its
length that permits it to move thmugh the smaller diameter tubing string
within the casing
15.
Figs. 4A - 4D show the mandrel 40 and portions thereof. Fig. 4B shows an O-
ring groove
46 and a stub acme thread 45. Fig. 4E shows the ratchet teeth (or buttress
threading) 48
that co-act with the teeth 88 of the latch 84.
Fig. SC shows the holes SS through which one or more shear pins SSa that
releasably hold
the slip 30 to the housing 50. The pins SSa extend from holes SSa (Fig. 2B)
into holes 35a
(Fig. 2A) of the slip 30.
Figs. 6A - 6D show the slip 30 with a slot 37 that moves on a corresponding T-
shaped
member 28 (see Fig. 7E) of the anchor body 20 as the slip exits the anchor
housing 50.
Figs. 7A - 7G show the anchor body 20 and parts thereof. Slips i 08 have a
dovetail cad
that fits in dovetail slots 26. A slot 24 facilitates connection of the anchor
body to the
concave 14 with bolts through holes 25. The male T 28 co-acts with the female
T-shape
of the slot 37 of the slip 30.
Fig. 8 shows one embodiment of a flexible hose 22. In one aspect such a hose
is a flwuble
metallic hose as is commercially available from Swagelok Hose Products.
Alternatively
a rigid or bendable tubular member may be used instead of the hose 22 or any
connection
...r mss.
or connection system that allows the required relative movement of parts.
Fig. 9 shows a hose adapter 16 with a channel 17 therethrough used with the
hose 22. The
adapter 16 has a recess 13 for an 0.ring to seal the adapter/anchor body
interface.
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Figs. l0A - 1 OC show a small slip 108 with a dovetail end 110 that is
received and held in
the con:espondingly shaped slots 26 in the anchor body 20 (sec Fig. 7C). These
small slips
108 engage an interior portion of the casing 15 opposite the portion engaged
by the slip 30.
As with the surface 31, a surface 109 may have any known type of teeth and/or
gripping
surface, marking and/or non-marking.
Figs. 11A and 11B show an anchor bolt 116 with a hex recess 118. Such bolts
are used to
joint the concave 14 to the anchor body 20.
to
Figs. 12A - 12E show a retrieval tool 130 according to the present invention
for retrieving
a whipstock or whipstock system from a wellbore; and, in one aspect, for
retrieving a
whipstock system 10 from a wellbore. The retrieval tool 130 has a body 132
with a channel
150 therethrough from top to bottom. A spring 152 has $ top end 158 biased
against a
shoulder 160 of the channel 150 and a lower end 162 biased against a member
154. The
member 154 has a channel 156 therethrough from top to bottom for fluid flow
and a lower
end 164. The fluid flow facilitates removal of debris, ete. from the concave
C.
A piston 138 is movably mounted in a channel 148 and urged outwardly
(downwardty in
2 o Fig. 12) by a spring 146 positioned in the channel 148 above the piston
138. A sleeve 134
encompasses the piston 138 and the member 154 and is connected to the body 132
e.g, by
welding and/or by threaded engagement.
A dog 144 partially in a slot 142 of the piston 138 and partially in a slot
166 of the member
154 initially releasably holds the piston 138 and the member 154 immobile.
A muleshoe profile 168 as is commonly known may be provided in the member 154
to
contact a to~of a~oncave C to facilitate correct orientation of the lip 136 of
the tool 130
with respect to a slot S of the concave C in casing G in a welIbore W that is
to be retrieved.
3 o The lip 136 of the sleeve 134 is sized, configured and positioned for
receipt within the lip
slot S of the concave C. (The concave C may be a concave of any known
whipstock, or it
may be like the concave of any whipstock disclosed herein). 'The concave C has
a surface
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F. The member 154 is initially reIeasably held by the dog 144.
Fig. 12F shows the tool 130 moved down with the bottom end of the sleeve 134
around a
top portion of the concave C and the lip 136 prepared to enter the slot S. The
end 140 of
the piston 138 has contacted the top of the concave C.
As shown in Fig. 12G, the lip 136 has entered the slot S and force is being
applied to the
piston 138.
As shown in Fig. 12H, the dog 144 has been released fmm the slot 166 by moving
adjacent
and into a reduced diameter portion or slot 120 of the piston 138, thus
freeing the piston
138 to move up in the channel 148 and freeing the member 154 which is urged
down by
the spring 152 so that a lower end 164 of the member 154 abuts the surface F
of the
concave C, thereby stabilizing the tool 130 on.the concave C. The lip 136 in
the slot S
stabilizes the concave in the up-down direction and the end 164 stabilizes it
in the side-to-
side direction. Retrieval of the concave C is now e$'ected by pulling upon a
string to which
the tool 130 is connected. The string may be a string of drill pipe or coiled
tubing (see, e.g.
coiled tubing string CT shown schematically, Fig. 3A and to which the system
is releasably
connected by any imown suitable connection apparatus CA) and may include a jar
and/or
2 0 a swivel.
When using the tool 130 with the system 10 of Fig., following sccurement of
the tool 130
to the concave 14, application of an upward force through the string to which
the system
10 is attached shears the pins 89 (e.g. at about 30,000 lbs) freeing the
pusher sleeve 60 to
move down (Fig. 3G) and allowing the slip 30 to retract within the housing 50.
Thus the present invention, in certain aspects, provides a through-tubing
retrievable
whipstock which can be s~ at any desired location in a wellbore or within a
tubular string,
..~e~ ~..
such as, but not limited to, a casing string, in a wellbore. In one aspect the
system is
3 0 hydraulically set and mechanically released (e.g. the system 10).
In one operation acco~ing to this invention, a system 10 according to the
present invention
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is inserted into and through tubing which has been run into casing in a
wellbore. The
system 10 is at the end of a string as previously described and descends
through the tubing,
exiting the tubing and entering casing within the wellbore. The system is
lowered to a
desired point in the casing.
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